Cross-roll



A ril 30, 1935. s. E. DIESCHER CROSS ROLL Filed May 24, -1933 INVENTOR 0W5 EM 7 M, awrvfhk ATTORNEYS.

Patented Ap 30, 1935 I UNITED STATES PATENT OFFICE CROSS-ROLL Samuel E. Diescher, Pittsburgh, Pa., assignor to Dlescher Tube Mills, Inc., Pittsburgh, Pa., a corporation of Delaware Application May 24, 1933, Serial No. 672,585

8 Claims. (01. 80- 13) My invention relates to apparatus for treating fore, be greater than that of the rolls when movcylindrical work-pieces by helically acting crossing at the same angular speed. This would cause rolls and particularly to means for assisting the twisting of the work-piece unless the collars were delivery of the products of such cross-roll app sitioned with relation to the rolls to bear so paratus therefrom and for regulating the diamlightly on the work-piece as to slip thereon, and 5 eters of the products thereof. it would be impractical to depend upon such slip In the operation of cross-roll apparatus having to avoid twisting of the work-piece. According helically acting rolls, dimculty sometimes occurs to the invention, twisting of the work-piece by in efiecting delivery of the treated product. This the action of the collars is avoided, or controlled is particularly true in the operation of cross-rollas desired, by providing a frictional slip-permit- 10 ing piercing'mills. As the trailing end of the ting driving connection between each collar and work-piece passes between the cross-rolls, the exthe roll with which it is associated, so that tent of surface contact between the rolls and the the collar, while acting to apply a driving work-piece becomes progressively less and the torqu to the WOIk-DieCeymeY assume h a e 15 force exerted by the cross-rolls on the billet is 0 Substantially the Same Peripheral Speed as h 15 correspondingly reduced and may, before the Work-piece, the collars being thus frictionally dIlV- work-piece is delivered from between the crossen to exert a limited torque on the wprk-rp rolls, become too weak to overcome the friction of My V ntiOn will be further descrlbed in conthe commonly used fixed guides, or, in a piercing nection with the accompanying drawing in which mill, to draw the trailing endof the billet over 115 eview,pertie11yin elevetidn and a ally 2 the mandrel point. in section, of a pair of cooperating cross-rolls pro- F'or the purpose of overcoming this difiiculty, ed with collars of my invention, a partially and for the further purpose of accurately regu- Pierced b l end a p 1' a mandrel belng lating the outside diameter of the pierced billets, shown n pe t ve p it ons etween the rol s;

piercing mills having cross-rolls of generally cy- F g. 2 is an enlarged longitudinal sectional view 25 lindrieal, or barrel, form have heretofore been of a portion of O Of the cellars of 3 provided with collars at the outlet end of the 'is a transverse sectional view taken on line rolls for engaging the pierced billets as they adm-III of Fig. and Us a transverse vance from the rolls. These outlet collars operate tional view taken on line IVIV of Fig. l.

on the billet in the same manner as the outlet Referring to the drawing, two conical cross- 30 surfaces of the rolls to rotate the billet and adrolls I and 2, which may be of the somewhat Vance it helically, thus exerting a longitudinal mushroom shape shown, or other suitable conical pull on the billet supplemental to that exerted by shape, are spaced apart to provide for the pasthe cross-rolls. Adjustment of these outlet colsage of work-pieces therethrough. The crosslars for taking up wear or for varying the distance rolls are mounted for operation in the usual man- 35 between their billet-engaging surfaces has been ner with the axes of their shafts 3 inclined to accomplished by tilting the roll shafts. Adjusteach other and to the line of feed of work-pieces m t of the collars in is way is, w v passing therebetween and skewed, that is, set at practical in a mill having conical rolls. different angles to a plane containing the center 40 According to the present invention, outlet 001- line of feed of the work-pieces and containing or 40 lars are provided on the rolls of-cross--rolling parallel to the shortest line between the rolls, so piercing mills and other cross-rolling mills havthat a helical movement is imparted to the working mushroom-shaped or other conical rolls, and piece. I adjustment of the collars to vary the distance be- Each of the cross-rolls l and 2 has associated tween their Work-engaging Surfaces to take up therewith at its outlet end an axially aligned col- 45 wear is provided for by mounting thecollars so as lar 4 which rotates with the roll in engagement to be adjustable axially toward and from the rewith the work-piece, and which in the construcspective rolls. Such axial adjustment of the 001- tion shown, instead of being mounted on an exlars gives the desired variation of the distance tension of the roll, is carried by a disc I0 slidably 5 between the collars because of the roll axes being keyed to the shaft 3 for rotation therewith and inclin d t the line of feed of the Workfor axial movement thereon to adjust the collar These outlet collars must, in order to engage 4 toward and away from the cross-roll. The discs the work-piece, be of greater diameter than the are retained in their axial positions relative to rolls with which they are associated, and the the cross-rolls by means of tension bolts 5 experipheral speed of the outlet collars will, theretending through these members and spacing bolts around the disc I0.

6. These bolts may be employed in any suitable manner, three of each being shown by way of example.

The spacing between the collars and the crossrolls is maintained by the adjustable bolts 6 which extend through the discs I and into engagement with the outer ends of the cross-rolls. Each of the bolts 6 is provided with a polygonal head I by means of which it may be adjusted, and a lock nut 8 by meansof which it may be secured in ada same angular velocity, either slippage must occur between the collars and the work-piece because of the relativelygreater frictional resistance between the cross-rolls and the work-piece, or the metal of the workpiece is twisted because of the higher peripheral speed of the collars.

If the rolls and the collars were rigidly connected for rotation together and'the collars were adjusted for relatively light pressure, slippage 50- the collarand its disc would occur. If, however, the collars were adjusted for relatively heavy pressure, while some slippage might occur the result would be to impart a considerable twist to the walls of the workpiece.

In ordertoavoid twisting or to regulate the degree of twisting, of the metal by the outlet 'collars, with the collars adjusted for a predetermined pressure on the work-piece to secure a desired feeding action or a desired reduction in diameter, I provide that slippage may occur between each collar and its carrying disc when thecollar is subjected to a torque resistance in excess of a predetermined maximum. value. The collars may thus rotate with the work-piece independently of the speed of the driving shaft and cross-rolls when the torque resistance exceeds that for which the collar is adjusted. A preferred form of frictional slip-permitting driving connection between detail in Fig. 2.

Each of the discs I0 is splined to its shaft 3 for rotation therewith, and is provided with a series of circumferential grooves I I in its peripheral face and two annular recesses I2. The collars 4 are of somewhat tapered cross-section to provide suitable bearing faces for engagingthe work-piece and eabhhas an internal flange I4 to extend into the outer annular recess I2 of its disc I0. An annular sleeve I 5 having at one end inner and outer flanges I6 and II, respectively, and having on its inner face a series of ribs of the disc, is provided for each collar and disc to serve as an adjustable friction bearing member.

Each sleeve I5 is divided into two or more segments in order that it may be placed in position When the sleeve I5 is in its I operative position, as illustrated in Figs. 1 and 2, its flange I6 extends into the inner recess I2 in the disc I0 and the flange I'I extends into an an- I9 in the collar 4. A series of bolts of which appears in Fig. 2, adjustnular recess 20, only one ably connects the collar and sleeve together degree of frictional engagement be-. tween the disc l0 and the grooved sleeve I5 and whereby the flange I4 of the collar 4 may be varied. 50 1 1- is illustrated in enlarged I8 to fit the grooves II mine the torque resistance under which the collar and sleeve will slip with respect to the disc I0. Ducts 2| and 22, having an outer closure 23, serve to convey any suitable lubricant to the friction surfaces.

Cross-rollsequipped with outlet collars accord ing to my invention may be employed for piercing billets, as shown in Fig. 1. It may be assumed that the mandrel 26, a portion of which is shown in Fig. 1 is, as usual, restrained from 1011'- gitudinal movement by any suitable means, such for example as a thrust bearing, not shown, for permitting rotation of the mandrel.

It may be assumed, also, that a billet 21 has entered the pass between the cross-rolls and has been pierced substantially to the degree shown in Fig. 1. Thereafter, as the billet progresses to the left, as viewed in Fig. 1, and the trailing end thereof nears the throat or point of narrowest space between the cross-rolls, it presents a pro gressively smaller area for engagement by the cross-rolls, and, because of this small area of engagement, it may occur that the longitudinal force exerted by the cross-rolls alone upon the billet is not sufficient to force the trailing end of the billet completely over the point of the mandrel to complete the piercing operation. However, the engaging surfaces of the collars 4, operating in the same manner as the outlet surfaces of the cross-rolls,.exert an additional longitudinal pull on the billet, and the piercing operation is by reason of this additional pull completed regardless of the sufliciency of the force exerted by the cross-rolls to accomplish the completion of the piercing operation.

In case the torque resistance on the collars 4 during the piercing operation exceeds the amount for which the frictional engagement of the grooves II and I8 is adjusted, slippage'will occur between the disc I 0 and the collars and sleeves I5 to permit the collars to drive the billet without, or substantially without, twisting it. The friction drive may be adjusted so that the collars will assume the same circumferential speed as that of the billet during actual piercing and so long as the cross-rolls retain their strong grip ,on the billet, but that as the piercing finishes and the cross-rolls lose their grip on the billet, the peripheral speed of the collars will increase with decrease in the torque resistance as thebillet is Danger of the trailing released from the rolls. end of the billet not passing over the mandrel point is thus avoided and the pierced billet is delivered quickly from the mill. I

In case of wear such as to reduce the diameter of the engaging surfaces of the collars, suitable adjustment may be made by means of the bolts 5 and 6 to shorten the distances between the crossrolls and the corresponding collars 4 to cause the latter to exert the desired pressure on the billet.

The frictional engagement between the grooves I I and ribs I8 and between the walls of the recess I2 and flange I4 may be regulated by adjusting the bolts 20, whereby twisting of the walls of the work-pieces by the collars 4 may be substantially eliminated or may be controlled as desired.

While cross-rolls provided with outlet collars in accordance with my invention have been illustrated and described as being employed in connection with the piercing of billets, it will be appreciated that the use of the collars is not necessarily limited thereto. The collars may be employed in connection with cross-rolling mills for wall thickness reduction and elongation of tubes and other cross-rolling mills in which it is desired to insure that the product of the mill is completely treated thereby and delivered therefrom after the completion of its operation, or for the purpose of varying and accurately delivering the diameters of products of the cross-rolling mills.

A further advantage from the use of the outlet collars is that the additional pull on the workpiece cxcrted by the collars has the effect of reducing the slippage between the work-piece and the rolls and thus increases the rate of forward movement of the work-piece.

I claim:

1. Cross-roll apparatus, comprising a pair of helically acting conical cross-rolls for treating work-pieces passing therebetween, means providing at the outlet end of each cross-roll a supporting surface concentri with the axis of the cross-roll, a collar of larger diameter than the cross-roll mounted on each such supporting surface to be frictionally driven to rotate with the cross-roll in engagement with the work-pieces, and means for adjusting the degree of frictional engagement by which the collar is driven to vary the torque resistance under which the collar will slip with relation to the cross-roll.

2. Cross-roll apparatus, comprising a pair of helically acting conical cross-rolls for treating work-pieces passing therebetween, an annular member mounted adjacent the outlet end of each cross-roll to rotate with the cross-roll in axial alignment therewith, a collar of larger diameter than the cross-roll mounted on each said annular member for engaging the work-pieces, and means providing friction driving connections between the collars and the annular members whereby the collars will be driven to rotate with the cross-rolls but will slip relatively to the annular members and cross-rolls under a predetermined torque resistance, said annular members being adjustable toward and from the respective cross-rolls to vary the distance between the workpiece-engaging surfaces of said collars.

3. Cross-roll apparatus, comprising a pair of helically acting conical cross-rolls for treating work-pieces passing therebetween, each of said cross-rolls being mounted on a shaft, a disc mounted for rotation therewith on each of said shafts adjacent the outlet end of the cross-roll and spaced therefrom and adjustable on the shaft toward and from the cross-roll, and a collar of larger diameter than the cross-roll mounted on each said disc for engaging the workpieces, and means providing friction driving connections between the collars and the discs adjustable for varying the torque resistance under which the collars will slip on the discs.

4. Apparatus for piercing billets, comprising helically acting conical cross-rolls for rolling a billet to advance it over a mandrel, a collar mounted at the outlet end of and in axial alignment with each of said cross-rolls to rotate therewith in engagement with the billet, said collars being adjusable toward and from the respective cross-rolls to vary the distance between the billet-engaging surfaces of the collars, and means for frictionally driving said collars to cause them to exert a limited torque on the billet.

5. Cross-roll apparatus, comprising a pair of helically acting cross-rolls for treating workpieces passing therebetween, and a collar in axial alignment with each of said cross-rolls at the outlet end thereof means for positively driving the cross rolls and means for frictionally driving the collars, said collars being formed to engage and exert a limited torque upon a work-piece by reason of said frictional driving connection.

6. Cross-roll apparatus, comprising a pair of helically acting, conical cross-rolls for treating work-pieces passing therebetween, each of said cross-rolls having at its outlet end in axial alignment therewith and adjustably spaced therefrom a collar of larger diameter than the cross-roll for engaging a work-piece, means for positively driving said cross rolls, and means for frictionally driving said collars whereby the collars exert a limited torque on a work-piece acted upon by the cross-rolls.

'7. Cross-roll apparatus, comprising a pair of helically acting conical cross-rolls for treating work-pieces passing therebetween, each of said cross-rolls having at its outlet end in axial alignment therewith a collar of larger diameter than the cross-roll for engaging a work-piece, means for positively driving each cross-roll, means for frictionally driving its associated collar whereby permitting different relative angular speeds of rotation of said collars with respect to the cross rolls, the angular speed of rotation of the collar being less than that of its associated cross-roll to exert a limited torque upon a work-piece engaged by the cross-rolls.

8. Cross-roll apparatus, comprising a pair of helically acting cross-rolls for treating work pieces passing therebetween, a collar in axial alignment with each of said cross-rolls at the outlet end thereof, and a common driving means for driving each of said cross rolls and its associated collar, means positively connecting said driving means to said cross-roll and means frictionally connecting said driving means to said collar, and said collars being formed'to engage and exert a limited torque upon a work piece by reason of said frictional driving connection.

- SAMUEL E. DIESCHER. 

